Saint Stephen climate

Saint Stephen Frost Dates and Growing Season

NOAA 1991-2020 normals for Rice, 8 km from Saint Stephen, elevation 1060 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Rice. A median date has an even chance of a later freeze in spring, or an earlier one in fall.

The last spring freeze typically comes around May 10 and the first fall freeze around September 29, a growing season of about 140 days.

Median at 36°F
last May 19, first September 21
Median at 32°F
last May 10, first September 29
Median at 28°F
last May 1, first October 7

Last freeze in spring

The chance of a later freeze than the date shown. At 10 percent, one spring in ten still freezes after the date; planting after the 10 percent date for 32°F is the cautious choice.

Threshold10%20%30%40%50%60%70%80%90%
36°FJun 1May 28May 25May 22May 19May 17May 14May 12May 8
32°FMay 22May 18May 15May 12May 10May 7May 5May 3Apr 30
28°FMay 12May 8May 5May 3May 1Apr 30Apr 27Apr 24Apr 20
24°FMay 4Apr 30Apr 28Apr 25Apr 23Apr 21Apr 18Apr 14Apr 9
20°FApr 26Apr 22Apr 19Apr 16Apr 14Apr 11Apr 8Apr 5Apr 2
16°FApr 20Apr 15Apr 12Apr 9Apr 6Apr 4Apr 2Mar 30Mar 23

First freeze in fall

The chance of an earlier freeze than the date shown. At 10 percent, one fall in ten freezes before the date.

Threshold10%20%30%40%50%60%70%80%90%
36°FSep 7Sep 12Sep 15Sep 18Sep 21Sep 23Sep 26Sep 29Oct 3
32°FSep 15Sep 20Sep 23Sep 26Sep 29Oct 1Oct 4Oct 7Oct 12
28°FSep 24Sep 29Oct 2Oct 5Oct 7Oct 11Oct 14Oct 18Oct 22
24°FOct 4Oct 9Oct 13Oct 17Oct 20Oct 23Oct 27Oct 30Nov 2
20°FOct 17Oct 22Oct 25Oct 29Oct 31Nov 2Nov 4Nov 7Nov 12
16°FOct 27Oct 31Nov 2Nov 4Nov 6Nov 9Nov 12Nov 15Nov 20

Growing season length

Days between the last spring and first fall freeze at each threshold, with the chance of a season at least that long.

Threshold10%20%30%40%50%60%70%80%90%
36°F140134130125122119115111105
32°F159152148144140137133129122
28°F177170166162159155151145139
24°F198192186182178175171166159
20°F216210205202198194190185178
16°F234226221217213209205201194

How often it gets that cold

The share of years with at least one night at or below each temperature.

36°F or colder
100% of years
32°F or colder
100% of years
28°F or colder
100% of years
24°F or colder
100% of years
20°F or colder
100% of years
16°F or colder
100% of years

Degree days

A degree day is one degree of the daily mean temperature beyond a base, for one day. Heating degree days count cold (the fuel a house burns), cooling degree days heat, growing degree days the warmth a crop needs; each crop has its own base.

Heating degree days, base 65°F
8,855
Cooling degree days, base 65°F
380
Growing degree days, base 40°F
3,933
Growing degree days, base 45°F
2,980
Growing degree days, base 50°F
2,144
Growing degree days, base 55°F
1,428
Growing degree days, base 60°F
828

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,71600
February1,42100
March1,16103
April708031
May33516194
June7675449
July21151595
August47101519
September21936286
October613263
November1,05003
December1,48900

What this means

NOAA computes these from the daily lows at the station over 1991-2020, fitting the dates of each year's last and first freeze to a distribution, so a date can be stated at any level of risk. 36°F is a frost risk for tender plants on a clear, calm night, since the ground cools below the air above it; 32°F is a freeze; 28°F is a hard freeze that kills most annuals.

The station is 8 km from Saint Stephen. Low ground, valleys and open fields freeze earlier and later than a town center or a hillside.

More

Sources

NOAA NCEI U.S. Climate Normals, 1991-2020, annual and seasonal normals for station USC00216920 (Rice). Public domain.